1. Field of the Invention
This invention relates to reduction of flavor permeation and absorption onto the walls of polyolefin plastic materials used for the packaging of dentifrice products.
2. The Prior Art
Tubes formed of polyolefin materials such as polyethylene have enjoyed wide commercial success in the packaging of many products. However, polyolefin materials such as polyethylene and particularly high density polyethylene are permeableto flavor oils and due to this permeability dentifrice compositions during storage in polyolefin tubes encounter a loss of flavor oils rendering the dentifrice less palatable. Manufacturers of dentifrices have attempted to minimize the flavor absorptive loss by using less permeable plastic tube materials wherever possible, but cost constraints limit the use of these materials in areas of the world where cost is a major factor in the purchase of the toothpaste product. Toothpaste manufacturers have increased the level of flavor in their products, to make up for the flavor lost in the permeable polyolefin plastic tubes but the extra cost of the additional flavor militates against this solution to the problem.
An ideal least cost remedy for the flavor absorption problem would be to prepare the dentifrice formulation in a simple manner whereby migration of the flavor onto the inner surface of the tube walls would be minimized.